21021626 has 8 divisors (see below), whose sum is σ = 31721760. Its totient is φ = 10447708.

The previous prime is 21021617. The next prime is 21021629. The reversal of 21021626 is 62612012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21021598 and 21021607.

It is not an unprimeable number, because it can be changed into a prime (21021629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31136 + ... + 31803.

It is an arithmetic number, because the mean of its divisors is an integer number (3965220).

Almost surely, 2^21021626 is an apocalyptic number.

21021626 is a deficient number, since it is larger than the sum of its proper divisors (10700134).

21021626 is a wasteful number, since it uses less digits than its factorization.

21021626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63108.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21021626 is about 4584.9346778335. The cubic root of 21021626 is about 275.9870906936.

Adding to 21021626 its reverse (62612012), we get a palindrome (83633638).

The spelling of 21021626 in words is "twenty-one million, twenty-one thousand, six hundred twenty-six".